I would like to be either a tank or DPS but im not sure what race to pick. One source claimed that it matter as to what race and spec you are to be effective.

Well it depends on what side your on. Dwarf's have an ability that helps out your defense if im not mistaken, Taurens have a bit more health than anyone on the Horde, it all depends. Its not really that big of a deal though, i would just go with whatever race you like best.

In most MMOs (wow included), the race is more about taste then practicality. It is true that some races, such as the dwarves, are more suited to tanking. However, in the end, your race is not going to matter that much.

the best race is get a fucking life and dont play retarded fucking games like that you stupid moronic fuck face

Well for tanking its nightelf because you get that extra dodge percentage or tauren for the extra health. For dps you need strength so dwarf, orc, or tauren.